Sheet feeder



4 Sheets-Sheet l e u mlm JNVENTOR. BYHOWARD PR/TCHARD H. A. PRITCHARDSHEET FEEDER llnlllnl April 15, 1952 Filed July 3o. 194e mm mm vm mmATTORNEUS April 15, 1952 H. A. PRITCHARD 2,593,181

SHEET FEEDER Filed July 50, 1946 4 SheetS-Shet 2 JNVENTOR.

OWARD A PRITCHARD B Maf/MMM,

ATTORNEJS April 15, 1952 H. A. PRrrcHARD 2,593,181

SHEET FEEDER Filed July 50, 1946 4v Sheets-Sheet 5 IN V EN TOR.

BYHowA RD A. PRITCHARD M7, pu afm ATTORNEYS April 15, 1952 H. A.PRrrcHARD 2,593,181

SHEET FEEDER Filed July 30, 1946 JNVENTOR.

E615 BYHowARD A. PR/TCHARD f@ wam/9% ww@ ATTORNEJS Patented Apr. 15,1952 SHEET FEEDER Howard A. Pritchard, Hiram, Ohio, assignor toHarris-Seybold Company, Cleveland, Ohio, a corporation of DelawareApplication July 30, 1946, Serial No. 687,074

23 Claims. 1

This invention relates to improvements inv sheet handling apparatus, andhas to do especially with a feeder for stream feeding sheets from theforward end of a pile or other supply of sheets.

Stream feeding as conventionally practiced in the feeding of sheets tomodern high speed presses involves separating the rear end of the topsheet from the supply, gripping the top sheet, blowing air forwardlybeneath the separated and gripped sheet to float the sheet, and movingthe sheet gripping means forward, thus permitting the moving blanket ofair beneath it to advance the sheet into the grip of pull-out rolls orthe like, whereupon the next sheet of the supply is taken and fedforward by the same procedure underneath the previous sheet.

While mechanism of this character has proven quite effective inpractice, it has certain limitations and gives rise to certaindifficulties when operated at very high speeds, or on especially largesheets, or on sheets which are in poor c-ondition for handling. Forexample, the forwardly directed blast of air must travel the length ofthe sheet and fully separate and float it before the sheet can bepermitted to start forward and the time required for this operationlimits the portion of each cycle available for other operations andtherefore limits the speed of the feeding. This limitation of coursebecomes more serious as the length of the sheet increases, and as theweight of the sheet or the amount of ink previously printed thereonincreases. Other factors such as waviness of the surface of the supplyand the presence of adjacent printed and unprinted areas on the sheetsinterfere with the efficient functioning of the air blast.

As a result of these and other factors, difficulty is experienced inattempting to feed sheets rapidly oif the supply to the pull-out rollsor conveyor singly and in accurately straight and accurately timedcondition. Since the accuracy of placement and timing of the sheets onthe conveyor directly affects the efficiency of the registering devicesto which the sheets are carried by the conveyor, the efficiency offeeding from the supply directly affects the productivity of theprinting press.

Attempts have been made to construct stream feeding mechanism operableat the front edges of the sheets but such devices have been cumbersomeand complicated and not adapted to high speed operation, and in somecases have involved momentary loss of sheet control during their cycleof operation.

In accordance with the present invention, a rotary feeding mechanismadapted to accomplish lapped feeding of sheets is contained in a compactcarrier at the forward end of the supply, which mechanism is driven bysimple driving connections and involves a minimum of reciprocatingparts. Sheet gripping units, preferably embodying one or more suckers,is operated to roll up the front edge of the top sheet, therebyseparating it from the sheet next below and permitting air to enterbetween it and the next sheet, the air being caused to enter byatmospheric pressure or by being blown under greater pressure from anozzle, not shown, provided for the purpose. When the sheet has beenlifted off the supply to a predetermined height and preferably withoutdisturbing its rear edge, a second sheet gripping unit in the samecarrier takes the sheet from the first gripping unit and raises it to anextent suicient to permit it to move forward over the top of thecarrier, whereupon it is taken by pull-out rolls or the like.

The carrier is transversely disposed and is preferably in the form of asector of a cylindrical drum, having arcuate surfaces which cooperatewith wheels adjacent the carrier to seize the sheets while still in thegrasp of the second gripping unit and thereafter advancing the sheets,the carrier and the wheels acting as pullout rolls.

One of the objects of the invention is the provision of simplified sheetfeeding means disposed at the front end of a sheet to be fed.

Another object is the provision of sheet feeding means operable under astream of fed sheets to seize the sheets of a supply in succession andtransfer them under positive control to the stream.

Another object is the provision of a feeding carrier which may bedisposed above and transversely of a supply of sheets, and which isadapted to lift the front edge of the top sheet off the supply and thenraise it and carry it over the top of the carrier into a stream ofsheets.

A further object is the provison of two sheet gripping units adapted tobodily rotate in the same direction around the same center and operableto transfer a sheet from one to the other of said units during theirrotation.

A further object is the provision of a sheety gripping sucker adapted tograsp a sheet by its upper surface and transfer it to sucker means forgripping the sheet by its undersurface, thelatter means serving also toraise the sheet further and advance it.

Still another object is the provision of driving means for imparting thedesired movements to the elements of the feeder.

Other objects and features of novelty will appear as I proceed with thedescription of that embodiment of the invention which, for the purposesof the present application, I have illustrated in the accompanyingdrawings, in which:

Fig. 1 is a fragmental plan View of a sheet feeder embodying theinvention.

Fig. 2 is a fragmental end elevational view of the same.

Fig. 3 is a sectional view taken on a vertical plane extending parallelto the direction of sheet travel, the feeder frame being omitted, and

Figs. 4 to 15 inclusive are diagrammatic end views of the feedingcarrier, showing the parts as they progress through a completerevolution of the carrier in twelve 36 stages.

Referring particularly to Fig. l, the side frame members of the feederare shown fragmentally at and 2l. Conventional means are provided forsupporting a pile P of sheets. A drum carrier 22 extends transversely ofthe machine directly above the forward edge of pile P. This carrier asherein illustrated consists of a cylindrical metal shell with end walls23 and 24, the cylindrical wall having therein a gap 25 for a purposewhich willpresently appear.

Frame member Y2li may have aligned bosses 26 and 21 on opposite surfacesthereof, and through these bosses and the frame member itself a bore 28is formed, constituting a bearing for a cylindrical element 29 whichcarries a plate 34 inside the frame, while outside the frame'it carriesa gear 3l and a cam 32. Gear 3l is driven by any suitable means from themachine to which sheets are to be fed. Plate 30 is secured by anysuitable meansto the end Wall 23 of the carrier.

At the opposite side of the machine end wall 24 of the carrier hasattached thereto by means of screws 33 or the like a plate 34 whichconstitutes the rotating element of a fluid valve. Plate 34 is boredcentrally to receive a trunnion 35 integrally formed with end wall 24and rotatably 'mounted in the frame member 2l. A thrust plate 35 issecured to the end of trunnion 35 `by machine screw 31. Between a boss33 on frame member 2l and the rotating plate 34 there is a fixed annularvalve plate 39 which may be held against rotation by screws 40 orequivalent means.

Within the cylindrical element 29 there vare bushings 4i which formbearings for a shaft 42, hereinafter called the main shaft. At the outerendof this main shaft there is keyed a pinion 43, and at its inner endwithin the hollow drum carrier there is a gear 44. Pinion 43 meshes witha gear sector 45 that is mounted to oscillate about a stud 45 anchoredin frame member Z. Sector 45 is oscillate-dby means of a rollerfollower' 4'! mounted upon the sector arm and running vupon cam 32.Follower 4l may be held against its cam 32 by any suitable spring means,not shown.

In bearings in the end walls 23 and 24V of the carrier I mount twohollow shafts 5l? and 5! parallel to mainshaftr42. Each of these hollowshafts carries one or more sheet-gripping units, illustrated herein assucker heads, one only for each shaft being illustrated. As shown hereina unit 52 on shaft 55 is disposed opposite a unit 53 on shaft 5|. Theseunits or heads may if desired be disposed in staggered arrangement, thatis, so as to engage different pcrgions of a sheet.

A single pair of such units may be suliicient for small sheets, butwhere larger sheets are to be handled, two or more pairs of units 52 and53 are employed at points properly spaced transversely of the machine.Unit 52 preferably carries a pair of flexible rubber suckers 54connected with the interior of hollow shaft by..a port 55, a cavity 55and a pair of passages 5l. Unit 53 as herein illustrated is formed ofmetal exclusively and is provided with a plurality of aligned passages58 which are connected with a cavity 59, the latter being incommunication through a port 60 with the hollow interior of shaf t 5 l.

Shafts 50 and 5I have pinned thereto gears 6I and 62 respectively, thesegears being of the same Ipitch diameter as gear 44. Mounted in the endwall 23 of the carrier and projecting inwardly into the carrier thereare two stub shafts 63 and Shaft 64 carries a double gear 66, oneelement of which meshes with gear 44 and the other element of whichmeshes with gear 62 on shaft 5I. Shaft 53 carries a single -gear 65which meshes with gear 44 and with gear 6i on shaft 50. Gears 55 and 65,being merely intermediate gears., may be of any suitable pitch diameterbut as shown they are of the same diameter as gears 44, 6I and 62.

Revolving plate 34 is provided with ports 10 and 1I which registerduring their rotation respectively with arcuate grooves l2 and 'i3formed in the face of fixed plate 39 and communicating with passages 12and 13' in plate 39, these latterpassages leading to an annular groove14 in the other face of the plate with which a conductor 'l5communicates, this conductor being connected with the intake end of anair-pump or vacuum chainber, not shown. The plates 34 and 39 thereforeconstitute valve means for controlling the suction in hollow shafts 50and 5i; Located above carrier 22 in position to cooperate with thearcuate surface thereof is a wheelt supported for free rotation insuitable bearings, not shown.

Operation- Shaft 42 with its gear 44 remains stationary except as itisvoscillated by sector and pinion 45, 43. Carrier 22, being xed withrespect to gear 3 I, turns continuously counterclockwise, as seen in thedrawings. Gears 65 and 66 therefore move like planet gears around a sungear 44, except as their movement is altered by the oscillation of gear44 due to the effect of the oscillations of sector 45 and pinion 43. Theterm turning as applied to shafts.50 and 5l or the sheet grippers 52 and53 carried thereby is used in a general sense covering either rotationor oscillation or oscillation superimposed upon rotation. If gear 44were allowed to remain stationary the gears 65 and 66 would roll evenlyaround gear 44 and by virtue of their engagement with gears 6I and 62would rotate each of these gears one complete revolution clockwisearound their respective centers while those centers were traveling onecomplete revolution counterclcckwise about the center of gear 4.4. Undersuch conditions, the gears 6I, 62 and their respective units 52, 53would travel bodily around the center of rotation of gear 44 and carrier22 but would remain always in fixed position with, relation to thevertical. For example, assuming the parts to be yin the position of Fig.V3 yand gear 44 to be held stationary, the suckers 54 wouldremain`disposed vertically downward .from .shaft 5D. and suction passages 58would remain disposed vertically upward from shaft 5I v,during theirtravel around gear 44.

The paths. of travel of .thesuction heads are altered from that justdescribed by the .oscillattion of gear 44 through the action of cam 32and sector 45. The oscillations of gear 44 are of course transmittedthrough gears 65, 66, gears 6I, 62, shafts 50, 5l to units 52, 53, andthese oscillations are superimposed upon the rotation produced by thesun and planet arrangement. Cam 32 is so shaped that the units 52, 53oscillate through an angle extending somewhat less than 90 degrees oneach side of the vertical, the amount of oscillation and the timingthereof being chosen to produce movement such that a point at the centerof one of the suckers 54 follows approximately the path designated A inFig. 4 and a point at the mouth of one of the suckers 58 followsapproximatey the path designated B in Fig. 4. The various stages in thismovement are illustrated in Figs. 4 to 15 inclusive.

In Fig. 4 the suckers 54 have just descended to the top of pile P or toa point above the pile close enough to attract and grip the top sheet ofthe pile. In Fig. 5 the carrier has turned through 30 from the positionof Fig. 4, thereby moving hollow shaft 50 rearwardly with respect to thedirection of feed. At the same time shaft 50 has turned clockwisethrough a sufficient arc to roll up the forward edge of the grippedsheet and thereby insure its separation from the sheet next below. Theseparating action may be assisted by fluffing air if desired in a mannerthat will be well understood by those skilled in the art. In this figurethe front edge of the sheet has been drawn a short distance into thecarrier through the gap 25. In the Fig. 6 position the two hollow shafts50 and 5I are turning clockwise and the adjacent surfaces of units 52and 53 are moving in opposite directions, the arcs of movement of thesuckers about their centers ybeing closely adjacent to each other andthe forward edge of the sheet extending further into the carrier. InFig. 7 the suckers 54 and 58 have come into alignment but the sheet isstill held by sucker 54. The front edge of the sheet now extends intothe carrier the maximum distance. In Fig. 8 the relative positions ofunits 52 and 53 are substantially the same as in Fig. 7, cam 32functioning to maintain them in this relation, but the advancing carrierhas lifted the sheet somewhat further. During the 1time the suckers arethus traveling together about the centers of the carrier, suction insuckers 54 is relieved and suction is established in suckers 58, so thatthe sheet is transferred from unit 52 to unit 53, it being noted thatunit 53 engages the underside of the sheet. Where the units 52 and 53are in alignment the breaking of suction in suckers 54 and establishingof suction in suckers 58 are substantially simultaneous, whereby thesheet is continuously under positive control and positive transfer ofthe sheet is obtained. Where the units 52. 53 are not in alignment thesuction in suckers 58 is preferably established before suction insuckers 54 is broken, so that both sets of suckers grip the sheet for atime during the transfer.

In Figs. 9, 10, 11 and 12, unit 53 rises gradually, meanwhile turningclockwise about its center, thus lifting the forward edge of the sheetand moving it outwardly toward the surface of the carrier.` In the Fig.13 position the suckers 58 have swung up through the gap 25 to aposition substantially flush with the surface of the carrier. As unit 53approaches the Fig. 13 position its motion is such that suckers 58 aretraveling at substantially the same linear speed as that of thev arcuatesurface of carrier 22. Shortly after the Fig. 13 position, and whilesuckers 58 are still gripping the sheet and traveling at carrier speed.the carrier presses the sheet against the underside of idler` roll 80,after which suction is broken in suckers 58 and they release the sheet.The driven carrier 22 and the idler roll 80 together constitute sheetpull-out means, and from this point on the sheet is in control of thesepull-out rolls. The driving effect of carrier 22 is of course limited bythe length of the arcuate surface of the carrier. In practice otherconveying devices such as tapes 8|, cooperating idler rolls 82, and afeed board 83, shown in Fig. 4, are provided which receive the sheetsfrom carrier 22 and roll 8D and convey them further toward the machinebeing fed, the stream of sheets being indicated in this gure by thebroken line S. The diameter and the speed of revolution of carrier 22are such'that the sheet is moved at the required speed. In the case of asheet by sheet'feeder this speed would ordinarily be approximately thesame as the surface speed of the printing cylinder of the press to whichthe sheets are fed, whereas for stream feeding it would be a fraction ofthat speed.

It will be noted that the unit 52 has swung gradually outward toward gap25 in passing from the Fig. 10 position to that of Fig. 14 and that inthe Fig. 14 position the sucker 54 is beginning to project through thegap. At the time of the Fig. l5 position follower 41 is at the highpoint of the cam 32 and stands as indicated by the broken line circle4l', Fig. 3. Thereafter the follower 41 runs down rapidly from the highpoint of the cam to the full line position of Fig. 3 which correspondswith the position of the sucker head in that figure and in Fig. 4, andthe sucker unit 52 swings rapidly in the clockwise direction from theFig. 15 position to that of Fig. 4. Then the follower 41 continues itsrapid travel down to the low point of the cam and position 41" of Fig.3, which corresponds to the positions of the sucker heads illustrated inFig. 6, the sucker unit 52 continuing its clockwise movement to causethe rolling up and lifting of the forward edge of the sheet. This rapidswing of the sucker unit 52 while the axis of the hollow shaft 50 movesthrough the lower portion of its travel results in a generally cycloidalpath of sucker movement, the center of the sucker travelingalong thecusp of path A as shown in Fig. 4 while the face of the sucker assumesdifferent angles with the top of the pile.

From the foregoing it will be seen that each sheet is gripped on itsupper surface by a-depending sucker, simultaneously rolled up andlifted, and presented to an upwardly extending sucker which followsalong after the depending sucker, when the two suckers come intoalignment in approximately tangential relation. It is then carried bythe second sucker upward and forward and placed in the bite between thecarrier and the idler roller. The next sheet is gripped and raised andfed beneath the preceding one, and with continued operation a stream ofsheets is formed and caused to advance above the carrier. Inasmuch asthe sheets, after being separated and lifted, are handled by theirundersurfaces, and inasmuch as the stream proceeds above the carrier andthe suckers and their driving connections are contained within thecarrier, difficulties heretofore encountered in efforts to stream feedsheets from the front of a pile are avoided. Control of the sheets bytheirz front edges, permitting them torbe pulled 4forward instead of`pushed or floated, is obviously advantageous.

Having thus described my invention, I claim:

l. In a sheet handling apparatus, a rotating carrier having its axistransverse to the direction of feed, two angularly'separated sheetgripping units pivotally mounted in said carrier, one of said unitsbeing adapted to take a sheet along a transverseedge thereof andmovesaid edge inwardly in the general direction of the carrier axis, meansfor turning said units about their pivots during rotation of thecarrier, said turning means causing the second unit to approach thegripped edge of the sheet, and means for causing the first unit torelease the'sheet and the second unit to grip it,'said turning meanscausing the second unit to carry the gripped edge of the sheet away fromthe axis of the carrier at a point angularly spaced from the takingpoint.

2. In a sheet handling apparatus, a rotating carrier 'having its axistransverse to the direction of feed'and having an Varcuate surfaceportion,

'two angularly separated sheet gripping units pivotally mounted in saidcarrier, one of said units being adapted to take a sheet along atransverse edge thereof vand move said edge into the space surrounded bythe path of said arcuate portion, means for turning said units abouttheir pivots during rotation of the carrier, said turning means causingthe second unit to approach the gripped edge of the `sheet within saidpath, means for causing the rst unit to release the sheet and the secondunit to take it, said turning means causing the second unit to carry thegripped edge of the sheet to the arcuate surface of the carrier, andmeans for pressing the sheet against said arcuate surface, said secondunit functioning to place the sheet gripped thereby into the bitebetween said arcuate surface and said pressing means.

3. In sheet handling apparatus, a rotating carrier, a first sheetgripper unit pivotally mounted in said carrier, means for operating saidfirst gripper unit to cause it to seize a sheet presented thereto andlift the same, sheet conveying means, a second sheet gripper unitpivotally mounted in said carrier, and means for operating said secondgripper. unit to cause its gripping portion to be disposed `opposite thegripping portion of said first unit with the lifted edge of the sheettherebetween for transferring the sheet from the rst unit to the second,and to cause the latter unit to ransfer the sheet to said conveyingmeans.

4. In a sheetfeeder, a rotating carrier, two angularly separated suckersin said carrier, and operating means for said carrier and suckerscausing one sucker to grip a sheet by its upper surface near its forwardedge, lift it oif the pile .and release it, and causing the other suckerto grip the release sheet by its undersurface at the time of its saidrelease and advance it, whereby it may be taken by sheet pull-out meansand moved forwardly over said carrier.

5. In a stream feeder for advancing sheets from a supply by theirforward edges, a rotating carrier disposed above the forward edge of thesupply, two angularly separated sheet grippers in :said carrier, andoperatingmeans for said carrier and grippers causing one gripper whilebelow the-'axis of the carrier to travel rearwardly across the top sheetof the supply, lift it off the supply and release it, and causing theother gripper to grip said lifted sheet and while above the axis of thecarrier advance it and release it, Y

and pull-out means to take the advanced'sheet, saidoperating meanscausing the next sheet 'of the supply to be taken, lifted, advanced andfed into said pull-out means beneath the preceding sheet.

6. In a sheet feeder, a rotating carrier, two: angularly lseparatedsheet gripping units mounted in said carrier to oscillate about .axesparallel to the carrier axis, and operating means forsaid carrier andunits causing'any givenpoint on the carrier to travel rearwardly whenbeneath'the carrier axisand forwardly when above ,said axis, and causingone of said units as it movesrearwardly to grasp a sheet simultaneouslylift it;and roll it rearwardly and then release it, and causing theother unit to grasp the sheet at the moment it is released and whilemoving forwardly advance it over said carrier.

'7. In a sheet feeder, a rotating carrier, two angularly separated sheetgrippers mounted in said carrier to oscillate about axes parallel to thecarrier axis, rand operating means for said carrier and grippers causingany given point on the carrier to travel rearwardly relative to thedirection of sheet feed when beneath the carrier axis and vforwardlywhen above said axis, causing one of said grippers as ittravelsrearwardly to move in a cycloidal path downwardly from the carrier torgrasp a sheet, then upwardly towardthe axis of the carrier and then torelease the sheet, and causing the other gripper to grasp the sheet atthe moment it is releasedand'while moving forwardly to advanceit overthe said'carrier.

8. In a sheet feeder, acarrier having 'an arcuate surface portion, meansfor rotating said carrier to cause the upper surface `thereof to turnforwardly relative to the direction of sheet feed,'two angularlyseparated sheet gripper units in said carrier, operating means for saidcarrier and gripper units causing one gripper unit as it movesrearwardly to grip a sheet, lift it andrelease it, and causing the othergripper unit to grip the lifted sheet at the moment of its release andadvance it over the carrier, and a pull-out roll cooperating with Asaidarcuate surface portion of the carrier for advancing the sheet 'after itis released by the second gripper unit.

9. In a sheet feeder, a drum carrier having a gap in itscylindrical'wall, two angularly lseparated sheet grippers mounted insaid carrier to oscillate about axes parallel to the carrier'axis,operating means for said carrier and grippers causing any given point onthe carrier to travel rearwardly relative to the direction ofsheet feedwhen beneath vthe carrier axis and forwardly when above said axis, andcausing one `of said grippersas it moves rearwardly to grasp the forwardedge of a sheet, lift itand draw it into the carrier through said gapand release it, and causing the other gripper to grasp the sheet andwhile moving upwardly and forwardly to project said forward edgeoutwardly through said gap` to the surface of the carrier.

l0. In a stream feeder for advancing sheets from a supply by theirforward edges, a rotating carrier disposed over the forward edge 4of thesupply, two angularly separated suckers in said carrier, and operatingmeans for said carrierand suckers causing one sucker while below theaxis of the carrier to travel rearwardly across the top sheet of thesupply, lift it oif kthefsupply and release it, and causing the othersucker to Vgrip said lifted sheet by its undersurface and Vwhile abovethe axis, of the `icarrierladvanceit andrelease it, and pull-out meansto take the advanced sheet, said operating means causing the next sheetof thesupply to be taken, lifted, advanced and fed into said pull-outmeans beneath the preceding sheet.

11. In a sheet feeder, a rotating carrier, two angularly separatedsuckers mounted in said carrier to oscillate about axes parallel to thecarrier axis, and operating means for said carrier and suckers causingany given point on the carrier to travel rearwardly relative to thedirection of sheet feed when beneath the carrier axis and forwardly whenabove said axis, causing one of said suckers as it travels rearwardly tomove in a cycloidal path downwardly from the carrier to grasp a sheet,then upwardly toward the axis of the carrier, and then to release thesheet, and causing the other sucker to grasp the sheet by itsundersurface and while moving forwardly to advance it over the saidcarrier.

12. In a sheet feeder, a carrier having an arcuate surface portion,means for rotating said carrier to cause the upper surface thereof toturn forwardly relative to the direction of sheet feed, two angularlyseparated suckers in said carrier, operating means for said carrier andsuckers causing one sucker as it moves rearwardly to grip a sheet by itsupper surface, lift it and release it, and causing the other sucker togrip the lifted sheet by its undersurface and advance it over thecarrier, and a pull-out roll cooperating with said arcuate surfaceportion of the carrier for advancing the sheet after it is released bythe second sucker.

13. In a sheet feeder, a drum carrier having a gap in its cylindricalwall, two angularly separated suckers mounted in said carrier tooscillate about axes parallel to the carrier axis, operating means forsaid carrier and suckers causing any given point on the carrier totravel rearwardly relative to the direction of sheet feed when beneaththe carrier axis and forwardly when above said axis, and causing one ofsaid suckers as it moves rearwardly to grasp the forward edge of asheet, lift it and draw it into the carrier through said gap and releaseit, and causing the other sucker to grasp the sheet by its undersurfaceand while moving upwardly and forwardly to project said forward edgeoutwardly through said gap to the surface of the carrier.

14. In a sheet feeder, a main shaft, a carrier rotatable about saidshaft, and means for grasping and moving a sheet comprising twooscillatable shafts mounted in said carrier parallel to said main shaft,a sheet gripper on each of said oscillatable shafts, a gear on said mainshaft Within said carrier gear means meshing with said main shaft gearfor turning said oscillatable shafts, a cam mounted to rotate with saidcarrier, a pinion on said main shaft externally of the carrier, a gearsector meshing with said pinion, a follower on said sector runningv uponsaid cam and oscillating said sector and thereby said main shaft, andmeans for imparting rotation to said carrier, said cam being so formedthat said grippers swing through arcs while their shafts revolve bodilyabout said main shaft.

15. In a sheet feeder, a main shaft, a carrier rotatable about saidshaft, and means for grasping and moving a sheet comprising twooscillatable shafts mounted in said carrier parallel to said main shaft,a downwardly directed sucker on one of said oscillatable shafts, anupwardly directed sucker on the other of said oscillatable shafts, agear on said main shaft within said carrier, gear means meshing withsaid main shaft gear for turning said sucker shafts, a cam mounted torotate with said carrier, a pinion on said main shaft externally of saidcarrier, a gear sector meshing with said pinion, a follower on saidsector running upon said cam for oscillating said sector and therebysaid main shaft, and means for imparting rotation to said carrier, thearrangement being such that while said sucker shafts revolve bodilyaround said main shaft the suckers oscillate about their shafts whilethey continue to extend downward and upward respectively.

16. In a sheet feeder, a main shaft, a carrier rotatable about saidshaft, and means for grasping and moving a sheet comprising twooscillatable shafts mounted in said carrier parallel to said main shaft,a downwardly directed sucker on one of said oscillatable shafts, anupwardly directed sucker on the other of said oscillatable shafts, agear on said main shaft within said carrier, gear means meshing withsaid main shaft gear for turning said sucker shafts, a cam mounted torotate with said carrier, a pinion on said main shaft externally of saidcarrier, a gear sector meshing with said pinion, a follower on saidsector running upon said cam for oscillating said sector and therebysaid main shaft, and means for imparting rotation to said carrier, saidcam being so formed that during rotation of the carrier said downwardlydirected sucker and said upwardly directed sucker face each othermomentarily, whereby a sheet may be transferred from one to the other.

17. In a sheet feeder, a rotating carrier, and means for grasping andmoving sheets comprising two oscillatable shafts mounted in said carrierparallel with the axis thereof, a sucker on each of said shafts, onesucker extending downwardly from its shaft and the other extendingupwardly from its shaft, said downwardly disposed sucker being adaptedto take a sheet from the top of a pile of sheets, the arcs of movementof said suckers relative to their axes being substantially tangent toeach other, and operating means for causing said suckers to come intoalignment for transferring sheets from the downwardly extending suckerto the upwardly extending sucker, and means for taking sheets from theupwardly extending sucker.

18. In a sheet feeding mechanism, a revolving carrier, two sheetgripping units oscillatably mounted in said carrier about axes parallelwith the carrier axis and angularly separated less than one of saidunits being adapted to grasp the forward edge of a sheet as the unitmoves bodily rearward in the lowermost part of its travel and then tolift the sheet, and the other unit being adapted to grasp the liftededge from a position beneath the sheet and to raise and advance it overthe top of the carrier, and driving means for bringing said units intosheet transferring relation during their upward bodily travel about saidcarrier axis.

19. In a sheet feeding mechanism, a revolving carrier, two sheetgripping units oscillatably mounted in said carrier about axes parallelwith the carrier axis and angularly separated less than 180, a sucker ineach of said units, the sucker in one of said units being adapted tograsp the forward edge of a sheet by its upper surface as the unit movesbodiy rearward in the lowermost part of its travel and then to lift thesheet, and the sucker in the other head being adapted to grasp theundersurface of the lifted edge and` raise the same and advance thesheet over the top of the carrier, driving means for bringing said unitsinto sheet transferring relation during their upward bodily travel, andmeans `for controlling` suction in said units to eifect'said transfer.

20. In sheet handling apparatus, a rotating carrier disposedtransversely to the direction of feed. two angularly separated sheetgripping units pivotally mounted in said carrier, one of said unitsbeing adapted to take a sheet along a transverse edge thereof, and meansfor turning said units about their pivots during rotation of saidcarrier for bringing the gripping portions of said units simultaneouslyinto the plane of the said pivots for transferring a sheet from saidsheet taking unit to vthe other unit.

21. In a sheet feeder, a main shaft, a carrier rotatable about said mainshaft, means for rotating said carrier, a second shaft mounted in saidcarrier. parallel to said main shaft, a first sheet gripper on saidsecond shaft, a gear on said main shaft, gear means meshing with saidAmain shaft gear for rotating said second shaft in a direction oppositeto that of the carrier, one revolution for each revolution of thecarrier, means for oscillating said main shaft and thereby superimposingupon the rotary motion of said second shaft a motion of oscillation,said oscillating means functioning to cause said first gripper to moveoutwardly from. the carrier axis .for

`grasping an edge vof a sheet and then to move the vgrasped edgeinwardly toward the axis of rotation of said carrier, a secondy sheetgripper mounted in the carrier adapted to take the grasped edge of thesheet from said first gripper and move it outwardly away from the axisof rotation of the carrier and means for taking the sheet vfrom saidsecond gripper and conveying it away from the carrier.

v22. In a sheet feeder, a main shaft, a carrier .rotatable about saidmain shaft, meansfor rotating said carrier, a second shaft mounted `insaid carrier parallel to said main shaft, a first ,sheet .gripper onsaidsecond shaft, a gear-on said main shaft, gear means meshing with`said main shaft gear for rotating said second shaft in a directionopposite tov that of the carrier, one revolution for each revolution ofthe carrier, a cammoun-ted to rotate with said carrier, a pinion on saidmain shaft, a toothed sector meshing with said pinion. a follower onsaid sector cooperating with said cam for moving said sector back andforth to oscillate said main shaft, and thereby superimpose upon therotary motion of said second shaft 'a motion of oscillation, saidoscillating means functioning to cause the sheet gripping portion ofVsaid first gripper momentarily to occupy a substantially stationaryposition for grasping an edge of a sheet and then to move the graspededge inwardly toward the Aaxisl of rotation of said carrier, a secondsheet gripper mounted in the carrier adapted to take the grasped edge ofthe sheet from .said rst gripper and move it outwardly away `from theaxis of the carrier, 'and means for taking the sheet from said secondgripper and conveying it away from the carrier.

23. In sheet handling apparatus, a rotating carrier, two angularlyseparated sheet grippers in said carrier, and operating means for saidcarrier and grippers causing one ,gripper to grip a sheet at its forwardVedge, move said edge inwardly toward the axis of the carrier andrelease it, and causing the other gripper `to meet the first gripper andto lgrip the forward edge of said released vsheet at the time of itssaid release and carry said'forward edge outwardy away from the axis ofsaid carrier and release it, and means for forwarding the sheet awayfrom said carrier.

HOWARD A. PRITCHARD.

REFERENCES CITED The following referencesv are of record in lthe file of`this patent:`

, UNITED STATES VPAIENTI'S Number

